Litter box



FIG. 1 is a perspective view of a litter box;

FIG. 2 is a right side view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines 3depict environmental subject matter, are for illustration only and are not part of the claim. 

CLAIM The ornamental design for a litter box, as shown and described. 